// 图片懒加载
function imgloading(){
    var  view1 = window.innerHeight || document.documentElement.clientHeight
    var  view2 = document.body.scrollTop || document.documentElement.scrollTop
    var  viewshow = view1 + view2
    var  viewobj = document.querySelectorAll("img")
    viewobj.forEach(function(item, index){
        if(item.offsetTop < viewshow)
        {
            item.src = item.getAttribute("sc")
        }
    })
}
imgloading()
window.onscroll = imgloading